JPS6241904B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering device for a traveling vehicle, and more particularly to a steering device for a traveling vehicle in which the front wheels and rear wheels can be steered and the driver's seat can be moved between forward and rearward positions. It is.

It is an object of the present invention to provide a steering device for a traveling vehicle that is capable of normal driving, four-wheel steering driving, and diagonal driving, and also allows driving in the same direction by the same steering operation even when driving forward or backward during each driving. It is.

Embodiments of the present invention will be described below with reference to the drawings.

A front wheel 2 and a rear wheel 3 are attached to the vehicle body 1 so as to be steerable, and a turntable 4 is attached to the vehicle body 1 so as to be rotatable. is provided.

The front wheel 2 is pivoted by a front steering cylinder 7, and the rear wheel 3 is pivoted by a rear steering cylinder 8.

P ₁ and P ₂ are first and second pumps driven by the engine E, and the discharge passage 9 of the first pump P ₁ is connected to the inlet port 11a of the front steering control valve 11 via the first flow divider 10. is,
The discharge passage 12 of the second pump P ₂ is connected to the inlet port 14 a of the rear steering control valve 14 via a second flow divider 13 .

The front and rear steering control valves 11 and 14 have inlet ports 11a and 14a as first ports.
and a second position connecting the inlet ports 11a, 14a to the second outlet ports 11c, 14c, and the spools 11', 14' are connected to the axle 15. Fixed, valve body 11″, 1
4'' is connected to a knuckle 17 via the front and rear steering control cylinders 16F and 16R, and the knuckle 17 is connected to the piston rods 7a and 8a of one of the front and rear steering cylinders 7 and 8. The tubes 7b and 8b of the front and rear steering cylinders 7 and 8 are pivotally connected to the vehicle body 1.

The tubes 16a of the front and rear steering control cylinders 16F and 16R are connected to a nutcle 17, and the pistons 16b are connected to the valve bodies 11'' and 14'' via outer cylinders, and are biased and held in a neutral position by a spring 18. In addition, the first and second chambers 16 ₁ and 16 ₂ are arranged.

Reference numeral 19 denotes a steering unit called Orbitroll (trade name), which is equipped with a metering device (gyrotor) 20 having a metering function and a manual switching valve 21, and its inlet port 19a is connected to the discharge of the second pump _P2 . The first and second outlet ports 19b and 19c are connected to the first and second chambers 16 of each of the steering control cylinders 16F and 16R.
₁ , 16, _{and 2} , and the manual switching valve 21 has a neutral position N where the inlet port 19a is directly connected to the drain port 19d, and an inlet port 19a.
and a first and second position connected to the first outlet port 19b and the second outlet port 19c through the motor 20, and when the first solenoid 23 is energized, the second solenoid ₂₃₂ is energized. Then it switches to the second position.

24 are the first and second chambers 16 ₁ and 16 ₂ of the front steering control cylinder 16F, the first and second outlets 19b of the steering unit 19,
19c, which is a first electromagnetic switching valve provided between the first and second pipe lines 25 and 26 that connects the first and second pipe lines 25 and 26, and which shuts off the first and second pipe lines 25 and 26 and closes the first and second chambers 16 ₁ , 1
₆ , a neutral position N that short-circuits the two, a first position that connects the first and second pipes 25 and 26, and a second position that connects the first and second pipes 25 and 26 in opposite directions. When the first solenoid ₂₇₁ is energized, the solenoid is switched to the first position, and when the second solenoid ₂₇₂ is energized, it is switched to the second position.

28 are the first and second chambers 16 ₁ and 16 ₂ of the rear steering control cylinder 16 and the second and first outlets 19 c and 1 of the steering unit 19;
This is a second electromagnetic switching valve provided between the third and fourth pipe lines 29 and 30 that connect the third and fourth pipe lines 2 to 9b.
9, 30 and the first and second chambers 16 ₁ , 16
Neutral position N, 3rd and 4th conduit ₂ , short-circuiting 2
9 and 30, and a second position where the third and fourth pipes 29 and 30 are communicated in opposite directions, and when the first solenoid 31 ₁ and the second solenoid 31 ₂ are energized, It is designed to switch between the first and second positions.

Reference numeral 40 denotes an electric circuit, in which a power source 41 is connected in parallel to the input terminals 43a and 44a of the front/rear changeover switch 43 and the mode changeover switch 44 via the main switch 42, and the front side terminal 43 of the front/rear changeover switch 43 is
b is the first solenoid 27 ₁ of the first electromagnetic switching valve 24
and the second output terminal 46c of the second relay 46, and the rear terminal 43c is connected to the first, second and third relay 4.
5, 46, 47 coils 45d, 46d, 47d
and the input terminal 47a of the third relay 47, and the mode changeover switch 44 has the first output terminal 44b, the second output terminal 44c connected to the input terminal 45a of the first relay 45, and the input terminal 46a of the second relay 46.
The first output terminal 45b of the first relay 45 is connected to the first solenoid 31 ₁ and the second output terminal 45 of the second electromagnetic switching valve 28.
c is the second solenoid 27 ₂ of the first electromagnetic switching valve 24
and the first output terminal 46b of the second relay 46
The second output terminal 47c of the third relay 47 is connected to the second solenoid ₃₁₂ of the second electromagnetic switching valve 28.

The fore/aft changeover switch 43 is provided between the vehicle body 1 and the turntable 4, and is connected to the front terminal 43b when the driver's seat 6 is in the forward position (when traveling forward), and is connected to the front terminal 43b when the driver's seat 6 is in the rearward position. It is configured to be connected to the rear terminal 43c when traveling in reverse (when traveling backwards).

Next, the operation will be explained.

As shown in FIG. 2, when the driver's seat 6 is in the forward position and the mode changeover switch 44 is in the position where it is connected to the first output terminal 44b (up to the normal running position), the first solenoid 27 ₁ of the first electromagnetic changeover valve 24 is excited and assumes the first position, and the second electromagnetic switching valve 28 assumes the neutral position N.

In this state, the first solenoid 23 ₁ of the solenoid valve 21
is excited to the first position, the discharge pressure oil of the second pump _P2 flows through the third flow divider 22, the inlet port 19a, the gerotor 20, the first outlet port 19b,
The piston 16b is supplied to the first chamber ₁₆₁ of the front steering control cylinder 16F through the first conduit 25, and the piston 16b extends (upward), and the valve body 11'' moves upward through the outer cylinder, causing the front steering control cylinder 11 is switched to the second position, and the discharge pressure oil of the first pump _P1 is transferred to the second outlet port 1.
Extension chamber 7 of steering cylinder 7 in front of 1c
₁ , the contraction chamber ₇ is supplied to the contraction chamber 72, and the front wheel 2 is swung left and right (arrow A) via the piston rod 7a and the knuckle 17.

At the same time, the tube 16a is moved downward by the nutcle 17, the valve body 11'' is moved downward via the spring 18 and the outer cylinder, and the front steering control valve 11 is moved to the neutral position N.
The front wheel 2 returns to the position and the front wheel 2 stops swinging at that position.
In other words, it has a follow-up function.

By repeating this operation, the front wheel 2
is steered to the right (see Figure 3), and the vehicle turns right (arrow B).

At this time, since the second electromagnetic switching valve 28 is held at the neutral position N, the rear wheels 3 are in a straight-ahead state.

When the driver's seat 6 is moved to the rearward position from the state shown in FIG. 2, the front/rear switch 43 is switched to the rearward position 43c as shown in FIG. 4, and the coil 47d of the third relay 47 is energized to the second output terminal. 47c, the second solenoid 3 of the second electromagnetic switching valve 28
1 ₂ is excited and becomes the second position, and the first electromagnetic switching valve 24 becomes the neutral position N.

In this state, the first solenoid 2 of the manual switching valve 21
3 When ₁ is excited and placed in the first position, the second pump
The discharge pressure oil of _P2 is supplied to the third flow divider 22, the inlet port 19a, the gerotor 20, and the first outlet port 19.
b The first chamber 16 of the rear steering control cylinder 16R via the fourth conduit 30 and the third conduit 29
₁ , the piston 16b extends (downward), and the rear steering control valve 14 is supplied to the second
position, and the discharge pressure oil of the second pump _P2 is switched to the second position.
It is supplied from the outlet port 14c to the extension chamber 8 ₁ and the contraction chamber 8 ₂ of the rear steering cylinder 8, and is supplied to the rear wheel 3.
is swung to the right via the piston rod 8a and the knuckle 17, and is steered to the right (arrow C) in the same manner as described above (see FIG. 5), and the vehicle turns right (arrow D).

In this way, when the operator operates the steering wheel in the same direction with the driver's seat 6 in the forward position (forward) and the rearward position (reverse), the vehicle turns in the same direction, making the steering operation easy.

In addition, as shown in FIG.
4 is connected to the second output terminal 44c (four-wheel steering running position), and the driver's seat 6 is in the forward position, the first and second electromagnetic switching valves 24,
The 28 first solenoids 27 ₁ and 31 ₁ are energized and switched to their respective first positions.

In this state, when the manual switching valve 21 is switched to the first position in the same manner as described above, the pressure oil discharged from the second pump _P2 is transferred to the front steering control cylinder 16.
It is supplied to the first chamber ₁₆₁ of the rear steering control cylinder 16R and the second chamber ₁₆₂ of the rear steering control cylinder 16R, and as described above, the front wheels 2 are steered to the right (arrow A) and the rear wheels 3 are steered to the left (arrow H). As shown in FIG. 7, the vehicle turns right (arrow B). This allows the turning radius of the vehicle to be reduced.

When the driver's seat 6 is placed in the rear facing position in the state shown in FIG. 6, the first and third relays 45, 4 are connected as shown in FIG.
Since the coils 45d and 47d of No. 7 are excited and current flows to the second output terminals 45c and 47c, the second solenoid 27 of the first and second electromagnetic switching valves 24 and 28
₂ and ₃₁₂ are energized and switched to their respective second positions.

In this state, when the manual switching valve 21 is set to the first position, the pressure oil discharged from the second pump _P2 is supplied to the second chamber ₁₆₂ of the front steering control cylinder 16F and the first chamber ₁₆₁ of the rear steering control cylinder 16R. As before, the front wheels 2 are steered to the left (arrow), the rear wheels 3 are steered right (arrow C), and the vehicle turns right (arrow D) as shown in FIG.

Therefore, when turning with a small turning radius by steering the front wheels 2 and rear wheels 3 in opposite directions, the same steering operation is performed with the driver's seat 6 in the forward position (forward) and backward position (reverse). This makes steering operations easier because the vehicle turns in the same direction.

In addition, as shown in FIG.
d (diagonal running position), the first output terminal 46b of the second relay 46 is energized, so the first solenoid 271 of the first electromagnetic switching valve 24 is energized, and the first solenoid ₂₇₁ is energized.
At the same time, the second solenoid ₃₁₂ of the second electromagnetic switching valve 28 is energized and becomes the second position.

When the manual switching valve 21 is switched to the first position in this state, the pressure oil discharged from the second pump _P2 is supplied to the first chamber ₁₆₁ of the front steering control cylinder 16F and the first chamber ₁₆₁ of the rear steering control cylinder 16R. The front and rear steering control valves 11 and 14 are respectively
As before, the front wheels 2 are steered to the right (arrow A), the rear wheels 3 are steered to the right (arrow C), and the first
As shown in Figure 1, the vehicle travels diagonally to the right (arrow G).

Furthermore, when the driver's seat 6 is moved to the rear facing position from the state shown in FIG. 10, the first and second electromagnetic switching valves 24 and 28 are moved to the first position and the second position as shown in FIG. Since it switches to the 2nd position, if you switch the electromagnetic switching valve 21 to the 1st position in this state, the 1st
Since the front wheels 2 and rear wheels 3 are steered to the right (arrows A and C) in the same manner as in the state shown in FIG. 0, the vehicle travels diagonally backward and to the right (arrow C) as shown in FIG.

Therefore, when the vehicle is traveling diagonally, the same steering operation is required to travel diagonally in the same direction whether the vehicle is traveling forward or backward, which simplifies the steering operation.

The present invention is as described above, and by switching the mode changeover switch 44, the front wheels 2 and rear wheels 3 can be steered in opposite left and right directions, or the front wheels 2 and rear wheels 3 can be steered in the same left and right direction. In addition to being capable of normal driving, four-wheel steering driving, and diagonal driving, when the driver's seat 6 is in the forward position and backward position, the excitation of each solenoid is switched by the front/rear switch 43, so that the vehicle can drive forward or backward during each driving. Vehicles can travel in the same direction with the same steering operation.

Also, the discharge oil from the first and second pumps P ₁ and P ₂ is supplied to the front and rear steering cylinders 7 and 8 via the front and rear steering control valves 11 and 14 via the first and second flow dividers 10 and 13. Therefore, a constant flow rate is always supplied, and the oil discharged from the second pump _P2 is always supplied to the steering unit 19 through the third flow divider 22 at a constant flow rate. The flow rate commensurate with the amount of operation is supplied to the front and rear steering control cylinders 16F, 1.
6R, so by operating the steering control unit 19, only the flow rate commensurate with the amount of operation is reliably supplied to the front and rear steering cylinders 7, 8. Furthermore, since it has a follow-up function, the amount of operation of the steering unit 19 can be controlled. When the front and rear wheels 2 and 3 are steered in proportion to this, the front and rear steering control cylinders 16F and 1
6R causes the front and rear steering control cylinders 11 and 18 to become neutral.

Therefore, the front and rear wheels 2, 3 can be reliably steered in accordance with the amount of operation of the steering unit 19.

Further, pressure oil is directly supplied from the first and second pumps P ₁ and P ₂ to the front and rear steering cylinders 7 and 8, and the oil discharged from the second pump P ₂ is transferred to the first and second pipes by the steering unit 19. Roads 25, 26 and 3rd
The front and rear steering control cylinders 16
Since pressure oil is supplied to F and 16R, when the steering unit 19 is operated, pressure oil is supplied to the front and rear steering cylinders 7 and 8 at the same time without any time delay, and the front wheels 2 and rear wheels 3 are steered at the same time. Combined with the above, it is possible to quickly and accurately perform steering commensurate with the operation of the steering unit 19.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram showing an embodiment of the present invention;
FIG. 2 is a detailed explanatory view of the main part, and FIGS. 3 to 13 are explanatory views of its operation. 1 is the vehicle body, 2 is the front wheel, 3 is the rear wheel, 6 is the driver's seat,
7 and 8 are front and rear steering cylinders, 1
1 and 14 are front and rear steering control valves, and 24 and 28 are first and second switching valves.

Claims (1)

[Claims] 1. In a steerable vehicle comprising a vehicle body 1 equipped with a pair of steerable left and right front wheels 2, 2 and a pair of left and right rear wheels 3, 3, a driver's seat 6 is provided movably between a forward position and a rearward position. , a front steering control valve 11 that supplies pressurized oil to the front steering cylinder 7 that steers the front wheels 2, and a front steering control cylinder 16F that switches the front steering control valve 11 are provided. The steering control cylinder 16F and the front steering cylinder 7 are connected through the knuckle arm 17 of the front wheel 2 so as to have a follow-up function, and pressurized oil is supplied to the rear steering cylinders 8, 8 that steer the rear wheels 3. A rear steering control valve 14 and a rear steering control cylinder 16R for switching the rear steering control valve 14 are provided, and a follow-up function is provided between the rear steering control cylinder 16R and the rear steering cylinder 8 via the knuckle arm 17 of the rear wheel 3. At the same time, the discharge passage 9 of the first pump _P1 is connected to the first pump P1.
connecting to the inlet port 11a of the front steering control valve 11 via a flow divider 10, and connecting the discharge passage 12 of the second pump _P2 to the inlet port 14a of the rear steering control valve 14 via a second flow divider 13; It is connected to the inlet side of the steering unit 19 via the third flow divider 22, and also connected to the first and second outlet ports 19 of the steering unit 19.
b, 19c to the first and second pipes 25 and 26 and the third and
The first and second pipes 25 and 26 are connected to the front steering control cylinder 16F via the first electromagnetic switching valve 24, and the third and fourth pipes are connected to the fourth pipes 29 and 30, respectively. Conduit 2
9, 30 are connected to the rear steering control cylinder 16R via the second electromagnetic switching valve 28, and the first electromagnetic switching valve 24 is connected to the first and second pipes 25, 26 and the first and second pipes 25, 26. 2 rooms 16 ₁ , 1
₆ , a neutral position N that short-circuits the two, a first position I that connects the first and second pipes 25 and 26, and a second position that connects the first and second pipes 25 and 26 in opposite directions. The second solenoid switching valve ₂₈ is switched to the first position when the first solenoid ₂₇₁ is energized and to the second position when the second solenoid 272 is energized. A neutral position N where the four pipes 29 and 30 are cut off and the first and second chambers 16 ₁ and 16 ₂ are connected by short circuit, a first position I where the third and fourth pipes 29 and 30 are connected, and a third and fourth pipes 29 and 30 are connected. a second position communicating the fourth conduits 29 and 30 in opposite directions;
The solenoid 31 ₁ and the second solenoid 31 ₂ are configured to switch to the first and second positions when excited, and the first and second solenoids 27 ₁ and 27 ₂ and the first and second solenoids 31 ₁ and 31 ₂ , a normal steering position where one solenoid is energized to steer only one of the front wheels 2 or rear wheels 3, and a normal steering position where the front wheels 2 and rear wheels 3 are rotated in opposite directions. a mode changeover switch 44 having a four-wheel steering position where the solenoid is energized to steer the vehicle; and a diagonal running position where the solenoid is energized so as to steer the front wheels 2 and rear wheels 3 in the same left and right direction; and a driver's seat 6. A steering device for a running vehicle, characterized in that a front/rear changeover switch 43 is provided for switching excitation of the solenoid when the solenoid is in a forward position and in a rearward position.